I'm wondering how much I can manipulate the metal - can it be
annealed and bent? - can it be soldered or should I be planning on
cold connection? and finally, how do I keep it from rusting?
I've done a fair amount of work with horse nails (new, not reclaimed)
and have found them nice to work with if you realize that you're
working with iron and not a copper based alloy.
to anneal: heat to a dull red and bury in warm sand or the like.
Leave buried until they're cold. The point is that you want them to
cool as slowly as possible.
to work: iron is best worked while red hot which is a dream because
it is like warm plasic at that temp, very easy to shape, twist, etc
(very satisfying work!). Annealing is a fair second option though
you'll find it will work harden quite quickly compared to sterling
and gold alloys.
soldering: I've never been very pleased with my efforts to silver
solder iron nails. It can be done, much depends on having a good flux
I'm told, but I've always found brazing (using a high temp torch like
oxy-acetylene) to be cleaner and, to my eyes, look better. Obviously
much personal bias there.
cold connection: personally, this is what I've found I prefer if for
no other reason than there's a certain syncronicity between nails and
rivets, or whatever, in terms of design aesthetics.
rust prevention: there are commercial treatments you can buy but
they're often pretty serious chemicals so I've always preferred and
used the old fashioned "blueing" technique.
blueing: clean and wire brush the finished piece so that you've
removed all scale, flux glass, etc, coat the piece in motor oil (a
light coat of used motor oil seems to work best, just a couple drops
smeared all over the piece with your fingers), gently bath the piece
in heat 'til the oil smokes (protect yourself from breathing that
smoke by the way and don't heat it so much that the oil actually burns
away), quench in salt water. For some reason I've never been able to
find a reference to this but quenching the blue in a mild brine seems
to build a better finish than quenching in plain water. Repeat this
process two or three times and you've got a nicely blued piece that
will stand up to normal wear and tear remarkably well. I've made
men's buckles out of horse nails and finished them this way: years
later they're still an attractive deep steely blue, the finish is
still in very good condition and no rust. Note that this type of
blueing is not satisfactory for pieces that will be worn next to the
skin since normal body moisture and salts will attack and destroy it
I hope some of this is useful to you.